Expanding rows in AdvanceDataGrid to Display Item renderers.

Hi,
I'm new to flex. I'm working on a requirement where I need to display data in AdvancedataGrid and making the rows expandable to display an ItemRenderer. I have used HierarchicalData to do the same. I've achieved my objective to an extent except for the error where all the rows gets expanded. Can anyone please help. If required I can share the code for the same.

I would like to ask you how are you creating data grid. Is it getting created dynamically in action script code or your are creating it using .mxml ?
If you are creating it using .mxml then you can increase span of data grid column. This example would help you find out the solution:
E.g.

You can paste some part of your code so that i can provide you exact solution.